Bi-directional fluidic elements and circuits

ABSTRACT

A bi-directional fluidic element includes an input-output passage which conducts incoming signals into interacting relationship with a fluid stream to deflect the latter in one sense towards an output passage. Outgoing signals deflect the fluid stream in an opposite sense to cause fluid to flow through the input-output passage in a direction opposite that of incoming signals.

United States Patent Bauer July 11, 1972 154] BI-DIRECTIONAL FLUIDICELEMENTS AND CIRCUITS [21] Appl. No.: 5,483

[52] 11.8. C1 ..l37/1, 137/816 [51] Int. ...E03b 1/00, F17d 1/00, F1501/14 [58] Field oISearch ..137/81.5,1

[56] References Clted UNITED STATES PATENTS 3,280,832 10/1966 Burns..137/8l.5 X 3,295,543 1/1967 ZaImanzon... ..137/81.5 3,467,125 9/1969Dexter ...137/81.5 3,192,938 7/1965Bauer.....,.......................... ..137/815 25 unuzmmu clacufl VENTsmuae GENERRTDR sum-mu 3,193,197 7/1965 Bauer ..137/81.5 X 3,366,1301/1968 Reader... 137/81 5 3,413,994 12/1968 Sewers... 137/81 5 3,457,9377/1969 Rainer 137/81 5 3,490,478 1/1970 Du BrueIer, Jr. 137/81 53,500,848 3/1970 Kelley A. ..137/81 5 3,529,616 9/1970 Davis "137/815Primary Examiner-Samue1 Scott Attorney-Rose & Edell ABSTRACT Abi-directional fluidic element includes an input-output passage whichconducts incoming signals into interacting relationship with a fluidstream to deflect the latter in one sense towards an output passage.Outgoing signals deflect the fluid stream in an opposite sense to causefluid to flow through the input-output passage in a direction oppositethat of incoming signals.

12 Claim, 6 Drawing Figures SIGNRL GENERI-TTDR C112L11T BACKGROUND OFTHE INVENTION The present invention relates to fluidic systems, and moreparticularly to apparatus and methods employing fluidic techniques forpropagating fluid signals bi-directionally over a single transmissionpath.

in many fluid-operated systems cost and space limitations make itdesirable to utilize a single signal transmission path to conductvarious signals between remote sub-systems. Where signal flow isuni-directional, that is all signals flow from one sub-system to theother, well-known multiplexing techniques can be employed to assure thattwo or more signals are not transmitted simultaneously. However, wherebi-directional fluid signal transmission is required, multiplexingtechniques by themselves are not sufiicient. For example, consider afluid-operated system of the type wherein each of two remote sub-systemsincludes a generating circuit which provides signals to be processed bya utilization circuit at the other subsystem. The primary drawback tousing a single fluid signal transmission path to propagate signalsbi-directionally between the sub-systems is the lack of proper isolationbetween the generating circuit and the utilization circuit at eachsub-system location. More particularly, it is necessary at eachsub-system to prevent the received signal from affecting the signalgenerating circuit, and to prevent the generated signal from affectingthe signal utilization circuit. in electronics this isolation is readilyachieved by utilizing diodes to block undesired signal flow. However,fluidic diodes developed heretofore have proven incapable of providingthe isolation required for most system applications. Consequently,fluidoperated systems must employ a different approach to achieveing thecircuit isolation required for bi-directional signal propagation in asingle flow path.

It is therefore an object of the present invention to provide a workablemethod for propagating fluids signals bidirectionally in a single flowpath.

It is another object of the present invention to provide a fluidicelement capable of receiving fluid signals at and transmitting fluidsignals from a single fluid passage.

It is another object of the present invention to provide a method andapparatus for transmitting fluid signals bidirectionally through asingle signal transmission path.

It is still another object of the present invention to provide a fluidicamplifier capable of amplifying fluid signals transmitted along a singlesignal transmission path in either of two directions.

Another type of fluid-operated system in which bidirectional fluid flowthrough a single transmission path is often advantageous is the fluidlogic system. For example, in electrical systems there are relays whichcarry current through their coils in either direction and thereby permittheir relay arms to provide a closure in either of two logic functionpaths. Since the contacts of the relay can carry current in eitherdirection, a single relay arm can conduct current in one direction whenforming part of one logic function path and in the other direction whenforming part of the second logic function path. There is no prior artfluidic analog of this electrical relay. Such an analog, as providedherein, would permit a considerable saving in the number of logicelements required to perform certain logic functions.

It is therefore another object of the present invention to provide abi-directional fluidic gate capable of selectively passing fluid signalsin either of two directions in accordance with existing logicconditions.

Another object of the present invention is to provide a bidirectionalfluidic gate capable of selectively passing signals in either of twodirections through a single flow path.

it is yet another object of the present invention to provide a method ofselectively permitting and inhibiting passage of fluid signals in eitherof two directions along a single fluid transmission path.

SUMMARY OF THE INVENTION In accordance with one aspect of the presentinvention a modified analog fluidic amplifier configuration is employedfor both receiving and transmitting fluid signals over a singlebi-directional transmission line. The amplifier is of the active typewherein a power stream of fluid is selectively deflected relative to oneor more receiver passages as a function of one or more input signals.One of the receiver passages is configured to conduct portions of thepower stream into the transmission path when the power stream isdeflected toward that receiver by a locally generated signal. The samereceiver passage is also configured to receive signals from thetransmission path and direct these signals into deflecting relationshipwith the power stream, whereby the power stream is deflected toward asecond receiver passage as a function of the signal received from thetransmission path. A signal utilization circuit receives signals fromthe second receiver passage. By using this element to receive andtransmit signals over a single bi-directional path, one avoids allinteraction between the local signal generating circuit and the localsignal utilization circuit at any sub-system location.

The amplifier interaction region is configured to permit an incomingsignal from the signal transmission path to be vented after deflectingthe power stream, as required. Depending upon the amplifierconfiguration, the amplification of signals in either direction can bemade linear functions of the input signal. The interaction region mayalso be configured to provide boundary layer effects in cases wheredigital signal transmission is desired.

More than one receiver passage may be configured to receive and transmitsignals in which case the element can be configured symmetrically toserve as a repeater amplifier. Such an amplifier would be located in abi-directional transmission line to amplify signals propagated in eitherdirection. The single repeater amplifier would thus compensate fortransmission line losses.

in another aspect of the present invention a bi-directional AND gate isprovided wherein three signal paths terminate at an interaction regionand are arranged such that the presence of any single signal produces nooutput signal and the presence of any two simultaneous input signalsproduces an output signal in a predetermined one of the signal paths. Inone embodiment the three signal paths are spaced mutually by and asignal provided by any one when none of the others are present isdirected to a respective one of three 120 spaced vent passages. A signalreceived by one of the signal paths can then selectively be transmittedto second of the signal paths when a signal is present at the thirdsignal path. Likewise, signals may be transmitted from the second signalpath to the first signal path if a signal is present at the third signalpath.

The bi-directional amplifier and the bi-directional AND gate may beemployed together or separately in fluidic systems to provide abi-directional flow capability in a single transmission path. inaddition, these elements may be employed in logic systems to achievebidirectional flow in a manner which substantially minimizes the numberof logic elements required to perform a given logic function.

BRIEF DESCRIPTION OF THE DRAWINGS The above and still further objects,features and advantages of the present invention will become apparentupon consideration of the following detailed description of specificembodiments thereof, especially when taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a diagrammatic representation of a circuit employing a pair ofbi-directional signal converter elements of the present invention;

FIG. 2 is a diagrammatic representation of a modified veron of theconverter element employed in the circuit of FIG.

FIG. 3 is a diagrammatic representation of still another modifiedversion of the converter element employed in the circuit of FIG. 1;

FIG. 4 is a diagrammatic representation of a bi-dlrectional AND gateprovided in accordance with one aspect of the present invention;

FIG. 5 is a diagrammatic representation of still another embodiment of abi-directional signal converter of the present invention; and

FIG. 6 is a plan view of a typical fluidic circuit employing theiii-directional elements illustrated in F108. 1 and 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG.1 of the accompanying drawings, there is illustrated a circuit employingtwo substantially identical fluidic elements 10 and I0 configured inaccordance with the principles of the present invention. Formation ofthe various nozzles, passages, and regions which comprise elements l0and 10' is accomplished in accordance with principles wellknown in thefluidics art and set forth, by way of example, in U.S. Pat. No.3,425,430.

Element 10 includes an interaction region 11 into which fluid in theform of a power stream issues via a power nozzle l3, to whichpressurized fluid (P+) is applied. Interaction region I1 is laterallyextended to form a left vented recess IS. The right side of interactionregion 11 is terminated by a sidewall 17 which is sufficiently remotefrom the power stream issued by a power nozzle 13 to prevent boundarylayer attachment of the stream to the sidewall. Left and right controlnozzles 19 and 21 respectively, are arranged to respond to applicationof pressurized fluid thereto, to issue respective control streams intothe upstream end of interaction region 11 on opposite sides of the powerstream issued by power nozzle 13. The control streams are preferrablyperpendicular to the power stream and interact therewith to providepower stream deflection to a degree dependent upon the relativestrengths of the control streams.

A central output passage 23 opens into the downstream end of interactionregion 11 on an axis coaxial with the longitudinal axis of power nozzle13. The width of central output passage 23 is such that the powerstream, when un-deflected, is received substantially in its entirety bythe central output passage. A left output passage 25, separated fromcentral output passage 23 by flow divider 27, communicates with the leftside of the downstream end of interaction region ll to receive powerstream fluid when the power stream is deflected to the left. The widthof passage 25 is chosen in accordance with the type of amplificationdesired; morc specifically, if pressure, flow, or power amplification isrequired, appropriate output passage widths may be selected inaccordance with the principles described in the aforementioned U.S. Pat.No. 3,425,430. A right outlet passage 29 is separated from centraloutput passage 23 by a flow divider 31 and is defined between flowdivider 3i and the extension of interaction region sidewall 17. Rightoutlet passage 29 is significantly wider than outlet passage 25. Moreparticular, outlet passage 29 is contoured to permit fluid flowtherethrough in both directions with minimal pressure loss.

Fluidic element 10' is substantially identical to fluidic element 10with the exception that each is a mirror image of the other.Consequently, the left side of element 10' corresponds to the right sideof element 10 and vice versa. The various nozzles, passages, and otherportions of element 10 are designated by the same reference numeralswhich designate corresponding parts of element 10 with the exceptionthat the numerals designating components of element 10' are all primed.

Bi-directional outlet passages 29 and 29' are interconnected via asingle fluid flow passage 33 which is likewise configured to permit flowin both directions with minimal pressure loss. In the usual caseelements 10 and [0' are located remote from one another. At the locationof element 10 there is a signal generator circuit 35, which provides asignal to be transmitted to the location of element 10' for use by autilization circuit 37'. Likewise, a signal generator circuit 35' at thelocation of element 10 provides a signal which is to be utilized byutitization circuit 37 at the location of element 10. The signalsprovided by circuit 35 and 35' are applied to control nozzles 19 and 19'respectively. Utilization circuits 37 and 37 are connected to receivesignals from outlet passages 25 and 25' respectively. The signalgenerator circuits 35 and 35' and the utilization circuits 3'7 and 37'may comprise conventional fluidic elements such as fluidic amplifiers ofboth the analog and digital types, fluidic switching elements, etc.

A bias signal may be applied to each of control nozzles 21 and 21' toposition the power streams of elements 10 and 10', respectively, asdesired in the absence of an input signal applied to either element.

In operation, assume that in the absence of signal applied to either ofelements 10 and 10', their respective power streams are directed towardcentral outlet passages 23 and 23'. Assume further that the centraloutlet passages of both elements are vented to ambient pressure. If asignal is provided by signal generator 35, a corresponding signal isprovided in outlet passage 29 by the deflected power stream of element10. This latter signal is transmitted along transmission path 33 and isreceived by passage 29' of element 10'. The received signal travelsthrough passage 29' into interaction region I! where it deflects thepower stream of element 10' toward outlet passage 25. The degree towhich the power stream of element 10' is thus deflected depends upon theamplitude of the signal received by passage 29. Correspondingly, thesignal in outlet passage 25, which is a function of deflection to theright of the power stream in element 10', is a corresponding function ofthe amplitude of the signal received by passage 29'. The signal inpassage 25' is then applied to utilization circuit 37 and is processedaccordingly. Analogous operation ensures when a signal is provided by asignal generator circuit 35' for use by utilization circuit 37. It isimportant to note that signals may be transmitted via path 33 in onlyone direction at a time; however, well-known fluidic switchingtechniques may be employed to assure that only one signal generatorcircuit is active at any one time.

An incoming signal received by either of passages 29 and 29' acts todeflect the power stream of the receiving element 10 and I0 sufficientlyto permit the incoming signal to be dissipated into the vented centraloutlet passage 23 and 23. There is thus no excessive pressure build upin the interaction regions II and II in response to an incoming signal.Moreover, elements 10 and 10' act as relatively high impedance signalreceivers due to the fact that, until the power stream is deflected bythe signals received on passages 29 and 29', the power stream closescentral channel 23 and 23' to incoming signal flow. in addition,elements 10 and 10', because of the configuration of passages of 29 and29', act as relatively low impedance signal sources when a signal fromgenerator circuit 35 and 35' is to be amplified and transmitted to aremote station. The end of passage 29 which communicates withinteraction region 11 is noted to be sufficiently wide to prevent unduepressure loss in signals being transmitted in either direction throughpassage 29. Of course, the same situation is true for passage 29'.

Various techniques well-known in the fluidics art may be employed totailor the gain characteristics of amplifiers l0 and 10' as desired. Forexample, the positive feed back approach described in U.S. Pat. No.3,468,323 may be employed to linearize the gain characteristics ofelements 10 and 10'. in addition, a further vent passage may communicatewith interaction regions II and l l through sidewall 17 and 17' ifdesired.

It will be appreciated that central outlet passages 23 and 23' need notbe vented but rather may be utilized to provide output signals fromtheir respective elements. Such signals vary inversely with any inputsignal applied to the elements.

Referring now to FIG. 2 of the accompanying drawings there isillustrated another fluidic element which is a modified version ofelements 10 and 10' of FIG. 1. More particularly, element 10" isconstructed substantially similarly to element 10' and has likecomponents designated with similar but double primed reference numerals.The difference between elements 10' and 10" resides in the fact that thesidewalls of interaction region 11" are contoured to permit a relativelysmall degree of boundary layer attachment thereto. Thus, sidewall 17"has a section at the upstream end of interaction region 11" which curvessufficiently close to power nozzle 13 to permit the power stream, whendeflected toward the left, to have such deflection enhanced by aboundary layer attraction to wall 17". Likewise, on the right side ofthe up stream end of interaction region 11', a wall section 18 isprovided to aid in deflection of the power stream toward the right oncethe power stream deflection in that direction has been initiated.importantly, when a deflecting signal is removed from element 10", theboundary layer attachments created by walls 17" and 18 are insufficientto retain the power stream, which consequently returns to its quiescentposition directed toward central vent passage 23". Element 10" is highlysuitable for digital signal transmission since the small amount ofpositive feedback effected by sidewalls l7" and 18 restore the leadingand trailing edges of pulse signals significantly.

Referring now to FIG. 3 of the accompanying drawings there isillustrated a fluidic element 40 which is another modified version ofelements 10 and 10 of F IG. 1. Element 40 includes an interaction region41 which receives a power stream of fluid from power nozzle 43. Left andright control nozzles 45 and 47 selectively provide control streamswhich interact with and deflect the power stream in interaction region41. The sidewalls of interaction region 4| are sufficiently removed frompower nozzle 43 and its longitudinal axis to prevent boundary layerattachment of the power stream to the sidewalls. A left vent passage 49and right vent passage 51 communicate between respective left and rightsidewalls of interaction region 41 and the ambient pressure environment.

A central outlet passage 53 is in alignment with power nozzle 43 andreceives substantially all of the power stream fluid issued by powernozzle 43 when the power stream is undeflected. Passage 53 may be ventedor not as desired. Left and right outlet passages 57 and 59 respectivelyare separated by respective flow dividers from central outlet passage53. Passages 57 and 59 are conventional in nature and are configured toconduct fluid flow in only one direction, namely away from interactionregion 41 when the power stream is directed to an appropriate one of theoutput passages. A further fluid divider separates left outlet passage56 from left input-output passage 61. Likewise, a right input-outputpassage 63 is separated by a flow divider from right outlet passage 59.Passages 61 and 63 are similar in configuration to passage 29 in FIG. 1and are arranged to conduct fluid flow in each of two directions.

in operation, the power stream in element 40 can be deflected to theright upon reception of a signal at either left control nozzle 45 orleft input-output passage 61. Then deflected to the right by suchsignals, the power stream provides some fluid flow to right outletpassage 59 and some fluid flow to right input-output passage 63. ln likemanner, a signal received by either right control nozzle 47 or rightinput-output passage 63 produces a deflection of the power stream to theleft so that a portion of the power stream flows into both left outletpassage 57 and left input-output passage 61. It may thus be seen that ifelement 40 is inserted in a transmission line with passages 61 and 63connected to respective sections of the transmission line, a signaltraversing the transmission line in either direction is amplified byelement 40. Likewise, element 40 can have a signal applied to either ofits control nozzles and thereby introduce an amplified version of thatsignal in either direction along the transmission line. The symmetry ofelement 40 permits this bidirectional amplification mode of operation.

The element of FIG. 3, in addition to providing repeater type actionwhereby it amplifies signals transmitted in either direction along thetransmission path to which it is connected, also provides independentoutput signals via output passages 57, 53, and 59. More particularly,these output passages may be employed to monitor signals beingtransmitted along the transmission line. In addition, element may beoperated as a conventional pure fluid amplifier of the analog type ifinputoutput passages 61 and 63 are vented and only output passages 53,57, and 59 are employed to receive the power stream as a function of theinput signals applied to control nozzles and 47. Likewise, outputpassages 57 and 59 can be deleted in their entirety if desired.

Referring now to H0. 4 of the accompanying drawings there is illustratedbi-directional AND-gate constructed in accordance with the principles ofthe present invention. In its preferred form, AND-gate 70 comprisesthree signal passages 7], 73, and 75, each capable of conducting fluidflow in either of two directions, and each having one end terminating atan interaction region 77. The ends of passages 71, 73, and whichcommunicate with interaction region 77 are mutually spaced by I20".Three vented passages 79, 81 and 83 also communicate with interactionregion 77 in a I20 spaced relationship. Vent passage 79 is alignedacross interaction region 77 with signal passage 71 so that flow fromthe latter, when undeflected, is vented via passage 79. In substantiallythe same manner, vent passage 81 vents undeflected flow from signalpassage 73 and vent passage 83, vents undeflected flow from signalpassage 75.

In one possible mode of operation for AND-gate 70 assume that passages73 and 75 are connected to respective sections 850 and 85b of a fluidsignal transmission line which interconnects two fluidic elements orcircuits. Assume further that a signal A is selectively applied tosignal passage 7]; that outflow from signal passage 73 to transmissionline section 85a is designated signal B; that input signal provided bytransmission line section 850 to signal passage 73 is designated signalC; that signal provided from signal-passage 75 to transmission linesection 85b are designated as signal D; and that signal provided bytransmission line section 85b to signal passage 75 are designated assignal E. It is noted that signal C, if applied alone to AND-gate 70, isvented via vent passage 8]. in fact transmission of signal C fromtransmission line section 85a to transmission line section 85b can beeffected only if signal A is present in signal passage 71. Likewise, inorder to provide signal B at transmission line section 850 in responseto signal E applied at transmission line section 85b, signal A must bepresent at input passage 7!. [f signal A is not present, signal E isvented via passage 83. Thus, the absence of signal A effectively blockspassage of signals between transmission line sections 85a and 85bregardless of direction whereas the presence of signal A permits thepassage of these signals in either direction. Again it should be pointedout that simultaneous signal passage in both directions is not possiblewith element 70 or with the elements discussed hereinabove.

It should be further pointed out that AND-gate 70 can serve to amplifysignals passing between signal passages 73 and 75 if signal A, appliedto signal passage 71 is a power stream and the angular spacing betweensignal passages 73 and 75 is ad justed to permit amplified power streamdeflection by signals C and E. Element 70, thus modified, closelyapproximates the configuration of element 40 in FIG. 3, opposite thecontrol nozzles and uni-directional output passages. in addition,element 70 can also be employed in a mode where the signal outpassage 71is bi-directional so that any combination of two signal passagesreceiving an input signal can provide a corresponding output signal atthe remaining signal passage. In any event, the angles between passages71, 73, and 75 must be chosen such that the relative momenta of twoinput signals in two of the passages produces a resultant signal in theremaining passage.

Logic systems requiring bi-directional signal transmission capabilitiesin certain channels are sometimes highly economical, particularly ininterlock circuits of some degree of complexity. A bi-directionalcapability can save as much as 50 percent in the number of elementsrequired as compared with the use of prior art uni-directional logicelements.

Referring now to FIG. of the accompanying drawings there is illustratedanother bi-directional element 90 which is capable of serving as anamplifier for signals traveling in each of two directions in atransmission line. More particularly, element 90 comprises aninteraction chamber 91 which is substantially oval shaped and isarranged to receive a power stream of fluid at its upstream end from apower nozzle 93. The downstream end of chamber 91 opens to a region fromwhich three fluid passages, 95, 97, and 99 extend. Passage 99 is alignedwith power noule 93 so that the power stream, when undeflected, isreceived by passage 99. Passages 95 and 97 extend in opposite directionsin mutual alignment and perpendicular to passage 99. A central vent bore96 is formed through either the top or bottom wall of chamber 91 inalignment with nozzle 93 and passage 99 so that the power stream, whenundeflected by a signal, does not attach to either sidewall of chamber91 and consequently flows through central passage 99. Fluid passages 95and 97 are designed to conduct fluid in either of two directions, andpreferrably are connected to respective portions of the transmissionline to permit bi-directional signal flow therethrough.

In the absence of a signal flowing in either direction in passages 95and 97, the power stream is received by central passage 99 and is eithervented or otherwise utilized as desired. If a signal is received inpassage 95 the power stream is deflected to the right, as viewed in FIG.1, so that a portion of the power stream fluid is peeled off by cusp 101which marks the intersection of the right sidewall of chamber 91 and onesidewall of input-output passage 97. The fluid thus peeled offrecirculates in a clockwise direction back upstream along the rightsidewall of chamber 91 to form a vortical flow pattern in the chamberand acts to deflect the power stream to the left. The power stream whendeflected to the left follows the contour of the left sidewall ofchamber 91 and thereby issues into right input-output passage 97. Thus,the signal received by input-output passage 95 causes the power streamto flow in input-output passage 97 and an amplified version of thereceived signal is transmitted further along the transmission line. Upontermination of the signal received by passage 95, the power stream,because of the venting of chamber 91 via bore 96, returns to its centralposition in which it is directed to central output passage 99.

In like manner, a signal received by input-output passage 97 deflectsthe power stream slightly to the left so that a portion of the powerstream fluid is peeled off by left cusp 103. The peeled off fluidrecirculates in a counter clockwise direction in chamber 91, deflectingthe power stream against the right chamber sidewall. The power streamwhen thus deflected issues into input-output passage 95 to therebyprovide an amplified version of the signal received by input-outputpassage 97. Element 90 thus provides a simple yet effective repeateraction for fluid transmission lines, permitting amplification of fluidsignals transmitted in either direction along the transmission line.

Referring now to FIG. 6 of the accompanying drawings there isillustrated in plan view a fluidic circuit employing elements l0 and ofFIG. 1 and element 70 of FIG. 4. More particularly, element 70 hassignal passage 7] arranged to receive a selectively actuable signal A.Signal passage 73 is connected to input-output passage 29 of fluidicelement 113 which is substantially identical to fluidic element 10 ofFIG. 1. Signal passage 75 of element 70 is connected to input-outputpassage 29' of fluidic element II] which is also substantially identicalto element 10' of FIG. 1. Right outlet passage 25' of fluidic element11! is connected to a control nozzle I15 of a fluidic OR/NOR-gate 7, forexample of the type illustrated in FIG. 3 of my US Pat. No. 3,246,66l.Right output passage of fluidic element I13 is connected to control port119 of fluidic OR/NOR-gate 121, for example of the same type as fluidicOR/NOR-gate H7.

To conform with the signal nomenclature employed in describing FIG. 4,consider an input signal C applied to control nozzle 19' of fluidicelement 113. The power stream of element 113 is deflected intoinput-output passage 19' thereof and is received by signal passage 73 ofbi-directional AND- gate 70. If signal A is not present at signalpassage 71. the amplified version of signal C is vented via vent passage81 and no signal is transmitted to element 111. If however signal A ispresent a signal is transmitted via signal passage 75 to inputoutputpassage 29' of element Ill. This signal deflects the power stream ofelement I11 toward right outlet passage 25' which in turn provides asignal to control nozzle of fluidic OR/NOR-gate 117. The latter respondsby providing signal D at its OR outlet passage 1 18.

A similar procedure ensures if an input signal E is applied to rightcontrol nozzle 19 of fluidic element lll. Signal E deflects the powerstream of element 1!] to input-output passage 29' thereof. This signalis vented by passage 83 in element 70 in the absence of signal A atsignal passage 71. If, however, signal A is present a signal is providedvia signal passage 73 at input-output passage 29' of element 113. Thissignal deflects the power stream of element 113 into right outletpassage 25' thereof and in turn to control nozzle 119 of OR/NOR-gate121. This results in provision of output signal B at the OR outletpassage 122 of gate 121.

FIG. 6 thus illustrates a logic circuit in which binary signals can betransmitted in either direction through elements Ill, 70, and 113. Ifanalog rather than digital signals are employed, fluidic OR/NOR-gates117 and 121 may be replaced by conventional analog fluidic amplifiers,and analog amplification provided by elements Ill and 113 may bepreserved. Likewise, as described above in relation to FIG. 4, byappropriately configuring element 70, the latter may also be used toeffect amplification.

While I have described and illustrated specific embodiments of myinvention, it will be clear that variations of the details ofconstruction which are specifically illustrated and described may beresorted to without departing from the true spirit and scope of theinvention as defined in the appended claims.

I claim:

1. In combination:

a single transmission path, having first and second ends, forpropagating fluid signals applied thereto in each of two directions;

generator means for applying a fluid signal to said first end of saidtransmission path for propagation to said second end; and

a fluidic element disposed at said second end comprising: an interactionregion; means for issuing a power stream of fluid into said interactionregion; an input-output passage arranged to conduct fluid in each of twodirections and having one end connected to said second end of saidtransmission path to permit fluid flow between said inputoutput passageand said transmission path, said input-out put passage having anotherend disposed to receive power stream fluid from said interaction regionwhen said power stream is deflected in a first sense and to issue fluidreceived from said generator means into said interaction region todeflect said power stream in a second sense opposite said first sense;input means for deflecting said power stream in said one sense; andoutput means for receiving power stream fluid from said interactionregion when said power stream is deflected in said second sense;

wherein said generator means comprises a second fluidic element ofsubstantially the same configuration as said first-mentioned fluidicelement, the input-output passage of said second fluidic element beingconnected to said first end of said transmission path.

2. In combination:

a single transmission path, having first and second ends. forpropagating fluid signals applied thereto in each of two directions;

generator means for applying a fluid signal to said first end of saidtransmission path for propagation to said second end; and

a fluidic element disposed at said second end comprising: an interactionregion; means for issuing a power stream of fluid into said interactionregion; an input-output passage arranged to conduct fluid in each of twodirections and having one end connected to said second end of saidtransmission path to permit fluid flow between said inputoutput passageand said transmission path, said input-output passage having another enddisposed to receive power stream fluid from said interaction region whensaid power stream is deflected in a first sense and to issue fluidreceived from said generator means into said interaction region todeflect said power stream in a second sense opposite said first sense;input means for deflecting said power stream in said one sense; andoutput means for receiving power stream fluid from said interactionregion when said power stream is deflected in said second sense;

wherein said generator means includes means for receiving and utilizingfluid signals transmitted from said second end to said first end of saidtransmission path; said combination further comprising bi-directionalfluidic gating means interposed in said transmission path forselectively inhibiting propagation of fluid signals along saidtransmission path in each of said two directions.

3. The combination according to claim 2 wherein said bidirectionalfluidic gating means comprises:

a further interaction region;

a first fluid signal passage for conducting fluid signals propagated inone of said two directions along said transmission path into saidfurther interaction region;

a second fluid signal passage for conducting fluid signals propagated inthe other of said two directions along said transmission path into saidfurther interaction region; and

control means for selectively directing fluid signals conducted intosaid further interaction region by said first fluid signal passage intosaid second fluid signal passage and for selectively directing fluidconducted into said further interaction region by said second fluidsignal passage into said first fluid signal passage.

4. The combination according to claim 3 wherein said control meansincludes a third fluid signal passage for issuing pressurized fluidapplied thereto into said further interaction region at an angle suchthat said pressurized fluid deflects fluid received from said firstfluid signal passage into said second fluid signal passage and deflectsfluid received from said second fluid signal passage into said firstfluid signal passage.

5. The combination according to claim 4 wherein said first, second andthird fluid signal passages are arranged to issue fluid streams intosaid further interaction region at angles of 120 with respect to oneanother, said fluidic gating means including means for venting from saidfurther interaction region all fluid which is conducted to but notdeflected in said further interaction region.

6. ln combination:

a single transmission path, having first and second ends, forpropagating fluid signals applied thereto in each of two directions;

generator means for applying a fluid signal to said first end of saidtransmission path for propagation to said second end; and

a fluidic element disposed at said second end comprising: an interactionregion; means for issuing a power stream of fluid into said interactionregion; an input-output passage arranged to conduct fluid in each of twodirections and having one end connected to said second end of saidtransmission path to permit fluid flow between said inputoutput passageand said transmission path, said input-output passage having another enddisposed to receive power stream fluid from said interaction region whensaid power stream is deflected in a first sense and to issue fluidreceived from said generator means into said interaction region todeflect said power stream in a second sense op posite said first sense;input means for deflecting said power stream in said one sense; andoutput means for receiving power stream fluid from said interactionregion when said power stream is deflected in said second sense;

wherein said interaction region has two sidewalls which are configuredto cause boundary layer effects between said power stream and saidsidewalls, said boundary layer effects being sufficient to aid anapplied force in deflecting said power stream toward each sidewall butinsufficient to maintain said power stream attached to said sidewalls inthe absence of said applied force.

7. The method of transmitting fluid signals between first and secondspaced locations wherein first and second fluidic amplifiers are locatedat said first and second locations, respectively, said amplifiers beingof the type wherein a power stream of fluid is issued into aninteraction region where it is selectively deflected relative to firstand second outlet passages, said method comprising the steps of:

transmitting power stream fluid of said first amplifier when received bysaid first outlet passage of said first amplifier to the interactionregion of said second amplifier via a fluid transmission passage and thefirst outlet passage of said second amplifier, the fluid thustransmitted being directed to deflectively interact with the powerstream of said second amplifier;

transmitting power stream fluid of said second amplifier when receivedby the first outlet passage of said second amplifier to the interactionregion of said first amplifier via said fluid transmission passage andthe first outlet passage of said first amplifier, the fluid thustransmitted being directed to deflectively interact with the powerstream of said first amplifier;

sensing deflection of the power streams of each of said amplifiers inaccordance with the fluid received by the second outlet passages of saidamplifiers. 8. The method according to claim 7 further comprising thestep of selectively gating fluid flowing in said fluid transmissionpassage to at will inhibit fluid transmission between said first andsecond amplifiers.

9. The method of transmitting fluid signals between first and secondspaced locations wherein first and second fluidic ele ments are locatedat said first and second locations, respectively, said elements being ofthe type wherein a common input-output passage conducts fluid signals ineach of two opposite directions, said method comprising the steps of:

transmitting fluid output signals from said first fluidic ele ment, whenreceived by the input-output passage of said first fluidic element, tothe input-output passage of said second fluidic element via a commonfluid transmission P g transmitting fluid output signals from saidsecond fluidic element, when received by the input-output passage ofsaid second fluidic element, to the input-output passage of said firstfluidic element via said common fluid transmission assage; and

sensing reception of fluid signals from said common fluid transmissionpassage at each of said input-output passages.

10. The method according to claim 9 further comprising the step ofselectively gating fluid flowing in said common fluid transmissionpassage to at will inhibit fluid signal transmission between said firstand second fluid elements.

1 1. in combination:

first and second fluidic elements each for generating fluid signals tobe transmitted and for receiving fluid signals, each of said fluidicelements comprising an input-output passage and means for sensing thedirection of fluid flow through said input-output passage;

a common fluid transmission passage extending between first and secondspaced locations;

wherein said first fluidic element is located at said first locationwith its input-output passage connected to one end of said common fluidtransmission passage in order to both receive from and transmit signalsto said second location; and

wherein said second fluidic element is located at said second locationwith its input-output passage connected to the other end of said commonfluid transmission

1. In combination: a single transmission path, having first and secondends, for propagating fluid signals applied thereto in each of twodirections; generator means for applying a fluid signal to said firstend of said transmission path for propagation to said second end; and afluidic element disposed at said second end comprising: an interactionregion; means for issuing a power stream of fluid into said interactionregion; an input-output passage arranged to conduct fluid in each of twodirections and having one end connected to said second end of saidtransmission path to permit fluid flow between said input-output passageand said transmission path, said input-output passage having another enddisposed to receive power stream fluid from said interaction region whensaid power stream is deflected in a first sense and to issue fluidreceived from said generator means into said interaction region todeflect said power stream in a second sense opposite said first sense;input means for deflecting said power stream in said one sense; andoutput means for receiving power stream fluid from said interactionregion when said power stream is deflected in said second sense; whereinsaid generator means comprises a second fluidic element of substantiallythe same configuration as said first-mentioned fluidic element, theinput-output passage of said second fluidic element being connected tosaid first end of said transmission path.
 2. In combination: a singletransmission path, having first and second ends, for propagating fluidsignals applied thereto in each of two directions; generator means forapplying a fluid signal to said first end of said transmission path forpropagation to said second end; and a fluidic element disposed at saidsecond end comprising: an interaction region; means for issuing a powerstream of fluid into said interaction region; an input-output passagearranged to conduct fluid in each of two directions and having one endconnected to said second end of said transmission path to permit fluidflow between said input-output passage and said transmission path, saidinput-output passage having another end disposed to receive power streamfluid from said interaction region when said power stream is deflectedin a first sense and to issue fluid received from said generator meansinto said interaction region to deflect said power stream in a secondsense opposite said first sense; input means for deflecting said powerstream in said one sense; and output means for receiving power streamfluid from said inTeraction region when said power stream is deflectedin said second sense; wherein said generator means includes means forreceiving and utilizing fluid signals transmitted from said second endto said first end of said transmission path; said combination furthercomprising bi-directional fluidic gating means interposed in saidtransmission path for selectively inhibiting propagation of fluidsignals along said transmission path in each of said two directions. 3.The combination according to claim 2 wherein said bi-directional fluidicgating means comprises: a further interaction region; a first fluidsignal passage for conducting fluid signals propagated in one of saidtwo directions along said transmission path into said furtherinteraction region; a second fluid signal passage for conducting fluidsignals propagated in the other of said two directions along saidtransmission path into said further interaction region; and controlmeans for selectively directing fluid signals conducted into saidfurther interaction region by said first fluid signal passage into saidsecond fluid signal passage and for selectively directing fluidconducted into said further interaction region by said second fluidsignal passage into said first fluid signal passage.
 4. The combinationaccording to claim 3 wherein said control means includes a third fluidsignal passage for issuing pressurized fluid applied thereto into saidfurther interaction region at an angle such that said pressurized fluiddeflects fluid received from said first fluid signal passage into saidsecond fluid signal passage and deflects fluid received from said secondfluid signal passage into said first fluid signal passage.
 5. Thecombination according to claim 4 wherein said first, second and thirdfluid signal passages are arranged to issue fluid streams into saidfurther interaction region at angles of 120* with respect to oneanother, said fluidic gating means including means for venting from saidfurther interaction region all fluid which is conducted to but notdeflected in said further interaction region.
 6. In combination: asingle transmission path, having first and second ends, for propagatingfluid signals applied thereto in each of two directions; generator meansfor applying a fluid signal to said first end of said transmission pathfor propagation to said second end; and a fluidic element disposed atsaid second end comprising: an interaction region; means for issuing apower stream of fluid into said interaction region; an input-outputpassage arranged to conduct fluid in each of two directions and havingone end connected to said second end of said transmission path to permitfluid flow between said input-output passage and said transmission path,said input-output passage having another end disposed to receive powerstream fluid from said interaction region when said power stream isdeflected in a first sense and to issue fluid received from saidgenerator means into said interaction region to deflect said powerstream in a second sense opposite said first sense; input means fordeflecting said power stream in said one sense; and output means forreceiving power stream fluid from said interaction region when saidpower stream is deflected in said second sense; wherein said interactionregion has two sidewalls which are configured to cause boundary layereffects between said power stream and said sidewalls, said boundarylayer effects being sufficient to aid an applied force in deflectingsaid power stream toward each sidewall but insufficient to maintain saidpower stream attached to said sidewalls in the absence of said appliedforce.
 7. The method of transmitting fluid signals between first andsecond spaced locations wherein first and second fluidic amplifiers arelocated at said first and second locations, respectively, saidamplifiers being of the type wherein a power stream of fluid is issuedinto an interaction region where it is selEctively deflected relative tofirst and second outlet passages, said method comprising the steps of:transmitting power stream fluid of said first amplifier when received bysaid first outlet passage of said first amplifier to the interactionregion of said second amplifier via a fluid transmission passage and thefirst outlet passage of said second amplifier, the fluid thustransmitted being directed to deflectively interact with the powerstream of said second amplifier; transmitting power stream fluid of saidsecond amplifier when received by the first outlet passage of saidsecond amplifier to the interaction region of said first amplifier viasaid fluid transmission passage and the first outlet passage of saidfirst amplifier, the fluid thus transmitted being directed todeflectively interact with the power stream of said first amplifier;sensing deflection of the power streams of each of said amplifiers inaccordance with the fluid received by the second outlet passages of saidamplifiers.
 8. The method according to claim 7 further comprising thestep of selectively gating fluid flowing in said fluid transmissionpassage to at will inhibit fluid transmission between said first andsecond amplifiers.
 9. The method of transmitting fluid signals betweenfirst and second spaced locations wherein first and second fluidicelements are located at said first and second locations, respectively,said elements being of the type wherein a common input-output passageconducts fluid signals in each of two opposite directions, said methodcomprising the steps of: transmitting fluid output signals from saidfirst fluidic element, when received by the input-output passage of saidfirst fluidic element, to the input-output passage of said secondfluidic element via a common fluid transmission passage; transmittingfluid output signals from said second fluidic element, when received bythe input-output passage of said second fluidic element, to theinput-output passage of said first fluidic element via said common fluidtransmission passage; and sensing reception of fluid signals from saidcommon fluid transmission passage at each of said input-output passages.10. The method according to claim 9 further comprising the step ofselectively gating fluid flowing in said common fluid transmissionpassage to at will inhibit fluid signal transmission between said firstand second fluid elements.
 11. In combination: first and second fluidicelements each for generating fluid signals to be transmitted and forreceiving fluid signals, each of said fluidic elements comprising aninput-output passage and means for sensing the direction of fluid flowthrough said input-output passage; a common fluid transmission passageextending between first and second spaced locations; wherein said firstfluidic element is located at said first location with its input-outputpassage connected to one end of said common fluid transmission passagein order to both receive from and transmit signals to said secondlocation; and wherein said second fluidic element is located at saidsecond location with its input-output passage connected to the other endof said common fluid transmission passage in order to both receive fromand transmit signals to said first location.
 12. The combinationaccording to claim 11 further comprising means located in said commonfluid transmission passage for selectively inhibiting fluid signaltransmission between said first and second spaced locations.